actually the light comes on the let you know a code has been stored. you check the codes by putting the key in the "on" position and turning the screw on the back of the computer. go to the left then to the right untill the LED begins to blink. count the blinks. shorts and long blink symbolize a 2 digit numer.

ex:

short short long long long --- 23

so forth and so on


i dont htin the bucking problem will be fixed by a simple code. its something loose or just mechanically broken. it IS a single cam and 9times out of 10, the motors are no good.